Franklin darracott



UNITE@ STATES PATENT TTICE.

FRANKLIN DARRACOTT, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO f GEORGE DARRAOOTT.

ilViPROVEIVl ENT IN DRY GAS-METERS.

Specification forming part of Letters Patent No. 12,045, dated December 5, 1854.

To @ZZ whom it may concern:

Be it known that I, FRANKLIN DARRAooTT, of Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Dry Gas-Meters, of which the following is a full, clear, and exact description, reference being had to the an-` nexed drawings, making part of this specification, in which- Figure lis a plan; Fig. 2, a section upon the line A A of Fig. l; Fig. 3, a front View, a portion of the case being removed to show the parts Within; Figs. 4 and 5, detached views of the valve and its seat, which will be referred to hereinafter; Fig. 6, an elevation of a portion of the inlet-pipe, showing the opening` a, through which the gas is admitted to the interior of the case which holds the measuringchambers; Fig. 7, a diagram, to which reference will be made hereinafter.

My invention has for its object the production of a uniform and unvarying stream of gas from the burner without the unsteadiness and jumping of the iiame, so often observed where dry or other gas-meters are employed.

The main feature of my invention consists in the use of four or more measuring-chambers, connected together in pairs, the chambers being brought successively into operation by the motion of two diaphragms so arranged that there shall at all times be an unvarying pressure upon the gas beyond the meter, the gas being forced from some one or other of the measuringchambers every instant that the meter is in operation.

My invention also consists in measuring the gas from the inside only of the chambers, in combination with surround-ing the measuringchambers with gas by opening a communication between it and the inletpipe,whereby all pressure is taken oic of the membranous substance which unites the disks, and all loss by transmission, as well as the possibility of registering more gas than is actually consumed, is avoided.

My invention also relates to certain details, which will be more particularly referred to hereinafter.

To enable others skilled in the art to ,make and use my invention, I will proceed to describe the method which I have adopted of carrying it out.

A is the box or case in which the operating parts of the meter are inclosed. It is made perfectly gas-tight and is in constant communication With the interior of the inlet-pipe G through the opening at a.

Bis a partition Vor stationary diaphragm, which divides the box A in two.

C C are the movable diaphragms.

b are flanges upon both the movable and stationary diaphragme, to which the iiexible substance D is secured. The flanges upon the movable diaphragms are of less diameter than those upon the stationary ones, as seen in the drawings, or vice versa, that the one may shut into the other for the purpose of rendering the full capacity of the chambers more nearly available. The diaphragnis C C are supported by arms E E, secured' to the vibrating shafts F F', which are thus set in motion by the motion of the diaphragms. yIhe latter are also further steadied in their motion by the arms H, which are pivoted to them at the points c, Figs. 2 and 3.

G is the inlet-pipe, from which the gas is conveyed by the channel L (shown dotted in red in Fig. 1) to the valve; I, the outlet-pipe, which receives the gas thro ugh the passage K. (Shown in dotted blue lines inFig. 1;)

The valve which I employ and the manner in which it is actuated by the diaphragms will now be described.

Fig. 5 is a plan of the Valve-seat, with the passages of communication between the valve and the measuring-chambers. Fig. 4 is a plan of the valve-cover and a section through its center.

rlhe gas from the inlet-pipe G and passage L rises through the center of the valve-seat d, Fig. 5, and enters the valve at e, Figs. 2 and 4. Thence it passes through the opening fdown one of the openings g of the valve-seat, through the channels M N O I), tothe measuring-chambers Q R S T. From these chambers it returns by the same channels, MN O P, up through the openingsg of the valve seat into the valvecover at the opening h. (Shown in blue in Fig. 4.) Thence the gas passes down through the opening fi of the valve-seat, which communicates by the outlet-passage K with the pipe I. Suppose the parts to be in such position that the opening f of the valve-cover just covers the opening g of the valveseat. The `gas e ranas from the inlet-passage L, as it passes through the center opening, d, of the valve-seat, Fig. 2, down through the opening f in the valvecover, enters the opening g of the valve-seat and passes by the channel M and vertical passage U to the chamber S. (Shown partially expanded by the pressure of the gas in Fig. 2.) At the same moment the opening h of the valve covers the ogening g2, which communicates th rough the passage O with the measuring chamber T, which is thus brought into connection with the outlet-pipel through the opening t' in the valve-seat and the passage K, and this chamber is thus emptied at the same time that the chamber S is being iilled. It will be observed that at the same time that the gas within the Vchamber S exerts a pressure upon the movable diaphragm C, and consequently upon the gas within the chamber T, there is an equal pressure from the gas within the case which holds the measuring-chambers upon the leather or other subst-ance which i'or'ms the flexible sides of the chambers, and consequent] y there is no loss of gas by transmission through the leather and no registry of gas not actually consumed. While the chamber S continues to fill and the chamber T to empty itself, the valve in its rotation brings Ythe inlet-opening f over the opening g of the valve-seat,through which the gas passes by the channel N and vertical pipe XV into the measuringchamber Q, which now commences to expand. The chamber R being at the same time brought into communication with the outlet-pipe T through the channel P and the vertical pipe X, both the chambers S and Q continue to expand, While R and T continue to collapse, until by the rotation of the valve the openingf has passed from off the opening g and now covers exclusively the opening g. The next instant it commences to cover the opening g2 in the valveseat, while the opening h at the Vsame time falls over q of the valve-seat and the gas begins to pour through the pipe() into the chamber T and from the pipe M out of the chamber S. The measuring-chambers are thus brought successively into operation, and at no instant is there a cessation or any interruption of the pressure within the outlet, which is at all times equal, or very nearly so, to that within the inlet-pipe, a difference only of pressure being produced by the friction of the moving parts; and it Will be observed that as the opening j' passes from off one opening, g, in the valve-seat it enters immediately upon another, so that as the passage through one of these openings diminishes that through the other increases, and there is consequently at all times a Way for the gas open through the valve equal to the size of the opening g. There can therefore be none of that iilckering of the :flame which is so often experienced-where dry gas-meters of the ordinary construction are used.

I will now describe the manner in which the valve and index are actuated by the motion of the diaphragms. These latter, as before explained, are pivoted or hinged to the arms E E', secured to the vertical rods F F', to which a vibratory motion is thus communicated by the motion of the diaphragms.

k k', Figs. 1 and 2, are arms secured 'to the rods F F and connected by means of thelinks Z Z to a crank-pin upon an arm, m, secured to the top of the valve-stem a.

o is a worm upon the valve'stem, which engages with a gear, p, upon the s haft g of the tirst index-hand. This shaft passes through a stuffing-box at B', by which the gas within the chamber Z is prevented from coming in contact with the mechanism ofthe counter. There being a free communication between the chambers Y and Z, the rods F F require no packing, and as there is thus an equal pressure upon all sides-` of the valve there is no tendency to leakage at this point.

From the connections above explained it is evident that from the vibratory motion ofthe diaphragms and of the rods F F a rotary motion is communicated to the valve, and to this end it is evident that the length of the arms k k must bear the same relation to that of the arms E E that the throw of the diaphragms does to the throw of the crank-pin t. Suppose the throw of the diaphragms be one and onehalf inch and the throw of the crank upon the valve-stem to be taken at one inch. Then the length of the arm 7c will be two-thirds that of the arm E, and it now only remains to nd the center of the valve. In the diagram, Fig. 7, let F F represent the position of the rods Construct an isosceles rightangle triangle on F F', making F F the hypoteneuse'. Lay oft' on the lines F l and F l the distances F a and F b', equal to the length of the arms k 7c', and sweep the arcs with these distances as radius. Then lay oft at equal distances upon each side of the lines F l and F l the points c' d and e f', so that the distance between these points shall be equal to the throw ofthe arms kk. Prolong the lines c c and ef until they meet in m', and this is the center of the valve, the circlea representing the path of the crank.

By opening a communication between the chambers Y and Z and permitting the gas to pervade these compartments of the meter, the necessity of packing the rods F F at any point is avoided, and I am enabled to make use of a lighter valve than would otherwise be required.

What I claim as my invention, and desire to secure by Letters Patent, is-

l. The use of measuringchambers arranged in pairs, as described, and similarly inclosed by means of the flexible leather secured to the stationary and movable diaphragms, the latter being placed between the chambers and forming one side of each of them and connected to the parts which they are 'to actuate by means of attachments to their peripheries, as set forth.

2. Ido not claim the method herein employed of giving motion to the valve, nor the system of arms, levers, 850., by which it is rotated, nor any arrangement or combination of such devices for effecting this purpose; but I bers, whereby an equal and uniform pressure do claim, in combination'with the measuringexists at; all times upon both sides of the leather chambers of a dry gas-meter, the within-dewhich unites the diaphragms, and all loss of scribed rotating valve, with its inlet and outigas by transmission through 'its pores is let-passages, constructed and operating in vthe avoided.

manner herein seb forth.

3. Opening a communication between the FRANKLIN DARRACOTT space which surrounds the measuringcham- VVit'nesses: bers and the inlet-pipe when the registering EDWARD G. LYNES,

takes piace only from the gas Within the cham- WILLIAM REED. 

